Epoxy functional silicone polymers capable of cationic cure either by photoinitiators or thermal initiators have been known in the art for some time. For example, Eckberg et al. in U.S. Pat. No. 4,279,717 discloses an ultraviolet-curable coating composition comprising (a) a precrosslinked epoxy functional dialkylepoxy-chainstopped polydialkyl-alkylepoxysiloxane copolymer fluid, and (b) a bis-aryl iodonium salt which is effective for catalyzing an ultraviolet light initiated cure reaction of the polydiorganosiloxane silicone intermediate fluid, which renders surfaces non-adherent to other surfaces which would normally adhere thereto, and which cures to a final non-adherent state upon brief exposure to ultraviolet radiation. Eckberg et al. further disclose that the adhesion of the coating composition to a substrate can be improved with the addition of .beta.-(3,4-epoxycyclohexyl)ethyltrimethoxy silane.
Koshar et al. in U.S. Pat. No. 4,313,988 discloses a crosslinked, polymeric network reaction product of starting materials comprising a curable epoxy-polysiloxane and optionally an epoxy-terminated silane, said materials are cured in the presence of a catalytically effective amount of an epoxy curing catalyst, which is useful as release coatings for adhesive roll and sheet materials.
Eckberg et al. in U.S. Pat. No. 4,421,904 discloses an ultraviolet curable epoxy functional silicone intermediate fluid composition comprising a pre-crosslinked epoxy functional dialkylepoxy-chainstopped polydialkyl-alkylepoxysiloxane copolymer silicone fluid which comprises the reaction product of: (a) a vinyl- or allylic-functional epoxide, (b) a vinyl functional siloxane crosslinking fluid, (c) a hydrogen functional siloxane precursor fluid, and (d) an effective amount of precious metal catalyst for facilitating an addition cure hydrosilation reaction between components (a), (b), and (c).
Kessel et al. in U.S. Pat. No. 4,822,687 discloses a composite structure comprising a substrate bearing on one or more surfaces a layer comprising an epoxypolysiloxane in which greater than 20% of the siloxane units are substituted by an oxiranyl group-substituted monovalent, non-cyclic, linear or branched aliphatic group, the epoxypolysiloxane being free of epoxy containing cycloaliphatic group-substituted siloxane units. Kessel et al. further discloses that the composite structures can be adhesive roll and sheet materials in which the novel layer is a release coating.
Eckberg in U.S. Pat. No. 4,987,158 discloses an ultraviolet radiation-curable composition comprising: (A) a pre-crosslinked epoxy-functional diorganopolysiloxane and (B) a catalytic amount of an onium salt photocatalyst or a combination of onium salt photocatalysts which are useful as conformal coatings, optical fiber coatings, and electrical encapsulation.
Eckberg et al. in U.S. Pat. No. 5,397,813 discloses an ultraviolet curable silicone coating composition comprising: (a) a polydialkyl-alkylepoxysiloxane fluid, (b) a pre-crosslinked dialkylepoxysiloxy- or trialkylsiloxy-chainstopped polydialkyl-alkylepoxysiloxane fluid, and (c) an effective amount of a bis-(dodecylphenyl) iodonium salt photocatalyst, the photocatalytic salt being selected from the salts of the group of acids consisting of hexafluoroantimonic acid, hexafluoroarsenic acid, hexafluorophosphoric acid, and tetrafluoroboric acid. Eckberg et al. further discloses that the silicone coating compositions of this invention are suitable as low release silicone coatings.
Eckberg et al. in U.S. Pat. No. 5,360,833 discloses an ultraviolet radiation-curable epoxysilicone composition comprising a blend of epoxy-functional silicone resins and epoxy-stopped silicone fluids which in the presence of an efficacious amount of onium photocatalyst is curable when exposed to ultraviolet radiation, the blend comprising: (A) about 60% by weight epoxy-functional silicone resin, the resin containing Q groups, epoxy functional M groups and at least one member selected from D groups and T groups, wherein the resin comprises at least 5 parts of the sum of M groups and epoxy-functional M groups per 10 parts of the sum of Q groups, D groups, and T groups; and (B) about 40% by weight epoxy-stopped silicone fluids containing epoxy-functional M groups, and the blend having an epoxy equivalent weight of greater than 1000.
Kobayashi et al. in U.S. Pat. No. 5,198,476 discloses an ultraviolet-curable silicone composition comprising (A) 100 parts by weight of an epoxy-functional polyorganosiloxane which comprises structural units represented by the formula R.sup.1 R.sup.2 SiO, wherein R.sup.1 represents a hydrogen atom or a monovalent hydrocarbon group and R.sup.2 represents a hydrogen atom, a monovalent hydrocarbon group, or a monovalent epoxy-functional organic group, and in which at least two of all the organic groups are a monovalent epoxy-functional organic group, (B) from 1 to 80 parts by weight of at least one copolymer for regulating peel strength, which is soluble in component (A), selected from the group consisting of (i) a copolymer represented by a unit structure of MQ or M.sup.A Q, (ii) a copolymer represented by a unit structure of M.sup.A T, MT.sup.A or M.sup.A T.sup.A, and (iii) a copolymer represented by a unit structure of M.sup.A DQ, MD.sup.A Q, or M.sup.A D.sup.A Q, wherein M represents an R.sup.3.sub.3 SiO.sub.1/2 unit, MA represents an R.sup.3.sub.2 R.sup.4 SiO.sub.1/2 unit, D represents an R.sup.3.sub.2 SiO.sub.1/2 unit, DA represents an R.sup.3 R.sup.4 SiO unit, T represents an R.sup.3 SiO.sub.3/2 unit, TA represents an R.sup.4 SiO.sub.3/2 unit, and Q represents an SiO.sub.2 unit, wherein R.sup.3 is a monovalent hydrocarbon group containing no alkenyl group and R.sup.4 is an alkenyl group, and (C) a catalytically effective amount of an onium salt as a photoinitiator.
Riding in U.S. Pat. No. 5,158,991 discloses a method for increasing the release force of an ultraviolet curable epoxy functional polydiorganosiloxane release composition comprising (A) an epoxy functional diorganopolysiloxane and (B) a catalytic amount of a photocatalyst or a combination of photocatalysts comprising (i) contacting (A) and (B) with from about 1% to about 30% by weight based on (A) of (C) a siloxane resin comprising monovalent R.sub.3.sup.2 SiO.sub.1/2 and R.sup.3 R.sub.2.sup.2 SiO.sub.1/2 units and tetravalent SiO.sub.4/2 units, the ratio of the monovalent units to tetravalent units being from about 0.6:1 to about 1.1:1, wherein R.sup.2 individually is a monovalent hydrocarbon radical of no more than 2 carbon atoms, R.sup.3 is a monovalent epoxy functional organic radical of from about 2 to about 20 carbon atoms, and the R.sup.3 R.sub.2.sup.2 SiO.sub.1/2 units comprising from about 1% to about 90% of the total number of monovalent units present, and (ii) dispersing components (A), (B), and (C) in (D) a hydrocarbon solvent in an amount sufficient to provide the composition with a solids content of from about 10 to about 50% by weight and a solvent content of from about 50 to about 90% by weight, the percentages being based on the total weight of Components (B), (C), and (D).
Riding in U.S. Pat. No. 5,310,601 discloses an improved ultraviolet radiation-curable epoxyfunctional silicone controlled release composition, comprising: (A) an epoxyfunctional diorganopolysiloxane having the general formula EQU R.sub.2 R.sup.1 SiO(RR.sup.1 SiO).sub.x (R.sub.2 SiO).sub.y SiR.sub.2 R.sup.1
wherein R is individually a lower alkyl radical having from 1 to about 8 carbon atoms; R.sup.1 individually is a monovalent cycloaliphatic epoxy-functional organic radical having from 2 to about 20 carbon atoms, "x" is a number ranging from about 1 to about 50, and "y" is a number ranging from about 1 to about 1000, (B) a catalytic amount of a photocatalyst or a combination of photocatalysts, and (C) from about 1% to about 30% by weight based on (A) of a siloxane resin comprising monovalent R.sub.3.sup.2 SiO.sub.1/2 and R.sup.3 R.sub.2.sup.2 SiO.sub.1/2 units and tetravalent SiO.sub.4/2 units, the ratio of the monovalent units to tetravalent units being from about 0.6:1 to about 1.1:1; wherein R.sup.2 individually is a monovalent hydrocarbon radical of no more than 2 carbon atoms, R.sup.3 is a monovalent epoxy functional organic radical of from about 2 to about 20 carbon atoms, and the R.sup.3 R.sub.2.sup.2 SiO.sub.1/2 units comprising from about 1% to about 90% of the total number of monovalent units present.
Eckberg in U.S. Pat. No. 5,369,205 discloses a UV curable epoxysilicone polymer comprising: the reaction product of a linear low molecular weight SiH containing fluid of the formula MD.sup.H.sub.X D.sub.Y M where M is R.sub.3 SiO.sub.1/2, D.sup.H is R(H)SiO.sub.2/2 D is R.sub.2 SiO.sub.2/2 x ranges from about 2 to about 50, y ranges from about 5 to about 500, and R is an aliphatic or aromatic radical and a M.sup.Vi MQ or M.sup.Vi MTQ resin having a ratio of M:Q of about 0.3:1.0 to about 2.5:1 and wherein the total weight % vinyl is about 0.5 to about 5.0 based on the weight of resin resulting in a hydrosilation partial reaction product and which hydrosilation partial reaction product is then reacted by hydrosilation with an epoxy containing unsaturated compound selected from aliphatic or cyclo aliphatic epoxies, said reaction product being an epoxy-functional silicone bearing pendant silicone Q resin moieties.